It has already been proposed (see German published specification No. 2,231,442) to provide transfer stations at road/rail junction points in which self-propelled carriages, movable in two orthogonal directions, serve for the transport of loads in a longitudinal or Y direction (parallel to a set of tracks) and in a transverse of X direction between road and rail vehicles. A hitherto unsolved problem in such a system is the control of traffic at the intersections of the longitudinal and transverse carriage paths.